Wyniki wyszukiwania - Biblioteka Nauki

1

Scheduling of tasks on moving executors using advanced evolutionary algorithms

100%

Józefczyk J.

Systems Science

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2003

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tom Vol. 29, nr 3

95-106

EN

The paper concerns the application of advanced evolutionary algorithms for solving a complex scheduling problem of manufacturing tasks. The case of scheduling of independent, non-preemptive tasks on unrelated moving executors, to minimize the makespan is considered. New heuristic solution algorithms based on an evolutionary computation are proposed. They use three different ways of multiple crossovers. The computer simulation experiments have been performed to investigate the dependence of results of the tasks scheduling on parameters of evolutionary algorithms as well as the quality of the solution algorithms in terms of the makespan and the time of computation. The evolutionary algorithms have been compared with a traditional solution algorithm that has been determined using the functional decomposition of the problem. A numerical example together with conclusions completes the paper.

2

New algorithms for solving the tasks scheduling problems in discrete manufacturing systems

100%

Józefczyk J.

Systems Science

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2003

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tom Vol. 29, nr 4

85-98

EN

The new algorithms for solving the tasks scheduling problem with moving executors to minimize the sum of completion times are considered. The corresponding combinatorial optimization problem is formulated on the basis of the formulations of the problems for the other scheduling performance indices. The heuristic simulation annealing solution algorithm is presented. It is compared with the evolutionary solution algorithm using computer simulation experiments. The influence of the parameters of the solution algorithm as well as the tasks scheduling problem on the quality of results and on the time of computation is investigated.

3

Application of genetic algorithms for solving the scheduling problem with moving executors

100%

Józefczyk J.

Systems Science

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2001

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tom Vol. 27, nr 1

87-95

EN

A new version of a genetic algorithm is proposed. For determination of crossover and mutation probabilities the learning algorithm is used. The algorithm is applied for solution of the tasks scheduling problem with moving executors. The learning procedure is performed with respect to different execution times in the scheduling problem. A basic scheme of genetic algorithm with generation of the initial population, selection and two reproduction algorithms is used. As the fitness function the makespan is assumed. The results of simulation experiments which evaluate the learning procedure as well as the effect of learning are presented. They show the slight improvement of the solution algorithm quality after applying the learning procedure for the crossover probability.

4

Szeregowanie zadań w kompleksie operacji z uwzględnieniem ruchu realizatorów - badania symulacyjne dla wybranych przypadków

100%

Józefczyk J.

|

1998

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tom z. 123

199-209

PL

Praca dotyczy problemu szeregowania zadań produkcyjnych w kompleksie operacji z uwzględnieniem ruchu realizatorów, traktowanego jako uogólnienie klasycznego problemu szeregowania. W tym zakresie podano algorytm rozwiązania problemu dla przypadku mnimalizacji maksymalnego opóźnienia oraz podstawy i wybrane wyniki badań symulacyjnych. W badaniach tych sprawdzano jakość rozwiązywania w zależności od danych problemu, takich jak: liczba zadań i realizatorów oraz czasy wykonania zadań.

EN

The problem of scheduling tasks on moving executors in complex operation system is considered in the paper. It is a generalisation of the classical scheduling problem. The solution algorithm, the foundations for simulation experiments as well as the selected results of simulation are presented. The evaluation of the solution algorithm with respect to ther data of the problem has been the purpose of the simulation.

5

Worst-case relative regret algorithm for task allocation in complex operation system

100%

Józefczyk J.

Systems Science

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2005

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tom Vol. 31, no 2

57-66

EN

The uncertain version of a task allocation problem in a complex of independent operations is considered. The parameters in models of the operations are assumed to belong to given intervals. The objective is to find a time-optimal robust solution in terms of the worst-case relative regret function. The optimal worst-case relative regret task allocation algorithm is presented. It consists in reducing the problem with uncertain input data to a number of deterministic problems whose solution algorithms are known. Special cases and a simple example for the polynomial models of the operations illustrate the solution algorithm.

6

On the problem f scheduling tasks on moving executors with random processing times.

100%

Józefczyk J.

Systems Science

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1999

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tom Vol. 25, nr 4

7-13

EN

The stochastic case of the tasks, scheduling problem with moving executors in a discrete manufacturing system is investigated. The perform manufacturing tasks moving executors drive-up to stationary workstations with plants located. In consequence, the routes for executors in the from of Hamilton cycles minimising the expected makespan should be determined. As the basis for further considerations the solution method for the deterministic case is given. Then the solution method as well as its evaluation are presented for the case of stochastic driving-up times.

7

Data driven score tests for univariate symmetry based on non-smooth functions

100%

Józefczyk J.

Probability and Mathematical Statistics

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2012

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tom Vol. 32, Fasc. 2

301--322

EN

We propose data driven score rank tests for univariate symmetry around a known center based on non-smooth functions. A choice of non-smooth functions is motivated by very special properties of a certain function on [0; 1] determined by a distribution which is responsible for its asymmetry. We modify recently introduced data driven penalty selection rules and apply Schwarz-type penalty as well. We prove basic asymptotic results for the test statistics. In a simulation study we compare the empirical behavior of the new tests with the data driven tests based on the Legendre basis and with the so-called hybrid test. We show good power behavior of the new tests often overcoming their competitors.

8

Analiza łącznego algorytmu szeregowania i sterowania w wybranym systemie transportowym

63%

Hojda M. , Józefczyk J.

Przegląd Elektrotechniczny

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2010

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tom R. 86, nr 9

111-114

PL

Praca dotyczy problemu szeregowania zadań, gdzie podmioty wykonujące czynności transportowe i produkcyjne mogą się poruszać. Zadania szeregowania i sterowania ruchem są powiązane: do wyznaczenia uszeregowania potrzebne są czasy przejazdu będące rezultatem sterowania, zaś sterowanie wymaga znajomości tras będących wynikiem szeregowania. W pracy porównano dwie wersje algorytmu rozwiązania tego problemu: algorytmu zdekomponowanego i iteracyjnego. Rozważania zilustrowano na przykładzie pojazdów o trójkołowym modelu jazdy.

EN

This work is concerned with a scheduling problem where elements executing transport and production tasks can move. Scheduling and control are interconnected. To derive a schedule, knowledge about movement times is essential. Likewise, control requires routes which are the result of scheduling. In this work, presented was a comparison of two solution algorithms: an algorithm with decomposition and an iterative algorithm. Deliberation was presented on a vehicle with a three-wheeled movement model.

9

Application of uncertain variables to production planning in a class of manufacturing systems

63%

Gąsior D. , Józefczyk J.

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2009

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tom Vol. 57, nr 3

249-256

EN

A production planning problem is addressed in the paper. It consists in the determination of a production plan of products to maximize a total utility connected with their manufacture taking into account a limited amount of resources of different types which are necessary for the production. An uncertain version of the problem is considered when an amount of the resources are not precisely known. The formalism of uncertain variables is proposed in the paper to solve this problem. The solution algorithms for two versions of the uncertain production planning problem are presented. It turned out possible to replace the uncertain problems by their deterministic counterparts. A simple numerical example illustrates the solution algorithms.

10

Algorithms for joint location-routing problem in a class of network systems

63%

Drwal M. , Józefczyk J.

Management and Production Engineering Review

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2011

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tom Vol. 2, No. 1

10-18

EN

In many decision making problems, the facility location and route design subproblems are commonly approached separately. This standard practice results in conceptually simpler models, but it often turns out to be too constraining and inaccurate. We propose a mathematical modeling framework of a wide applicability that enriches the locational analysis with the routing aspect, and leads to joint location-routing binary optimization problem. The usefulness of this general framework is presented through an application example in a merchandise delivery of online shopping companies (business-to-consumer e-commerce). Other applications for logistic systems as well as for computer systems are also described and justified. The main advantage of the proposed approach comes out from the precise contrasting suppliers' and consumers' needs. Moreover, if a repeated relocation of facilities is under consideration then taking the long-term planning horizon into account is necessary to obtain realistic and competitive results. Static and dynamic versions of the optimization problem are introduced for which the heuristic solution algorithm based on the Lagrange relaxation and the dynamic programming approach are respectively presented.

11

Towards dedicated decision support tools: CLP-based approach

63%

Banaszak Z. , Józefczyk J.

Applied Computer Science

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2005

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tom Vol.1, no 1

161--180

EN

Constraint programming (CP) is an emergent software technology for declarative description and effective solving of large combinatorial problems especially in areas of integrated production planning. In that context, the CP can be considered as a well-suited framework for development of decision making software supporting small and medium size enterprises in the course of Production Process Planning (PPP). The problem considered regards of finding of computationally effective approach aimed at scheduling of a new project subject to constraints imposed by a multi–project environment. In other words, we are looking for an answer whether a given production order specified by its cost and completion time can be accepted in a given manufacturing system specified by available production capability, i.e., the time-constrained resources availability. The problem belongs to a class of multi-mode case project scheduling problems, where the problem of finding a feasible solution is NPcomplete. The aim of the paper is to present the CP modeling framework as well as to illustrate its application to decision making in the case of a new production order evaluation. So, the contribution emphasizes benefits derived from CPbased DSS and focuses on constraint satisfaction driven decision-making rather than on an optimal solution searching.

12

Scatter Search based algorithms for min-max regret task scheduling problems with interval uncertainty

63%

Józefczyk J. , Siepak M.

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tom Vol. 42, no. 3

667--698

EN

Uncertain versions of three task scheduling problems: P║Cmax, F2║Cmax, R║Σ Cj are investigated. Parametric uncertainty is only considered which is represented by intervals. It is assumed that values of execution times of tasks are not a priori given, and they belong to the intervals of known bounds. No distributions additionally characterizing the uncertain parameters are assumed. The regret is used as the basis for a criterion evaluating the uncertainty. In a consequence, min-max regret combinatorial problems are solved. Heuristic algorithms based on Scatter Search are proposed. They are evaluated via computational experiments and compared to a simple middle intervals heuristics and to exact solutions for small instances of the problems considered.

13

Decision-making for supply chains with transportation and production units

63%

Józefczyk J. , Filcek G.

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tom Vol. 33, no 1

53-59

EN

The paper concerns a supply chain system, that consists of three interconnected sub-systems (stages): a set of raw material warehouses, a set of production units and a set of product warehouses. The purpose of the decision-making for such a system is the allocation of a raw material among parallel production units and the determination of the transportation plans for the raw material and the product to minimize the total cost. In the paper, two versions of the decision-making problem are formulated. In the first one, all decisions are made jointly. The second simplified version consists in a consecutive determination of optimal allocation of the raw material and both transportation plans. The problem formulation for both cases are given. The equivalence condition of both versions for the simple case is presented. The numerical example completes the paper.

14

An algorithm for joint location, coverage and routing in wireless sensor networks

63%

Jagusiak S. , Józefczyk J.

Journal of Theoretical and Applied Computer Science

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2013

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tom Vol. 7, nr 3

61--71

EN

This paper deals with selected joint problem of location, coverage and routing in a class of wireless sensor networks. The minimization of the total cost of data collection and transmission as well as sensors and sinks location is considered. Its NP-hardness is justified and a heuristic solution algorithm based on the result of the circulation problem in a directed graph is proposed. The quality of the algorithm has been assessed during numerical experiments, and the examples of corresponding results are presented.

15

Evolutionary algorithm for minmax regret flow-shop problem

63%

Ćwik M. , Józefczyk J.

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2015

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tom Vol. 6, No. 3

3--9

EN

The uncertain flow-shop is considered. It is assumed that processing times are not given a priori, but they belong to intervals of known bounds. The absolute regret (regret) is used to evaluate a solution (a schedule) which gives the minmax regret binary optimization problem. The evolutionary heuristic solution algorithm is experimentally compared with a simple middle interval heuristic algorithm for three machines instances. The conducted simulations confirmed the several percent advantage of the evolutionary approach.

16

Wykorzystanie algorytmów ewolucyjnych do rozwiązania wybranego problemu szeregowania zadań z ruchomymi realizatorami

63%

Józefczyk J. , Thomas W.

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2002

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tom z. 134

233-242

PL

W pracy jest rozważane specyficzne, proste zagadnienie szeregowania zadań, w którym należy uwzględniać ruch realizatorów. Ograniczono się do szeregowania zadań niezależnych i niepodzielnych na realizatorach dowolnych w celu minimalizacji długości uszeregowania. Do rozwiązania sformułowanego problemu optymalizacyjnego zastosowano i przedstawiono dwie wersje algorytmu ewolucyjnego. Zaprezentowano wybrane rezultaty badań symulacyjnych, w których dokonano eksperymentalnej oceny rozpatrywanego algorytmu rozwiązania.

EN

Scheduling of manufacturing tasks on moving executors for a simple case is considered in the paper. The problem of independent and non-preemptive tasks as well as unrelated executors with makespan as the performance index is investigated. The corresponding optimization problem is formulated and solved using two versions of an evolutionary algorithm. The results of simulation experiments, which verify the quality of the solution algorithm, are given.

17

Algorytm sterowania dwupoziomowym kompleksem operacji produkcyjnych

63%

Józefczyk J. , Orski D.

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2000

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tom z. 129

191-200

PL

Przedstawiono algorytm sterowania dla kompleksu operacji produkcyjnych, w którym łącznie są rozpatrywane: wybrane zagadnienie szeregowania zadań oraz zagadnienie bezkolizyjnego sterowania jazdą grupy realizatorów w celu minimalizacji długości uszeregowania. Prezentowany algorytm ma charakter adaptacyjny, a mianowicie rozwiązania w postaci tras przejazdów dla realizatorów są modyfikowane w trakcie działania algorytmu. Przedstawiono wyniki badania wrażliwości uzyskiwanego rozwiązania na zmiany liczby zadań i liczby realizatorów.

EN

The problem of control in a complex manufacturing operation system is investigated. Two interconnected sub-problems, i.e. scheduling of manufacturing tasks and control of movement of a group of executors performing the tasks are solved to minimise the makespan. The adaptive solution algorithm is given, which allows current modifications of routes for executors. The results of sensitivity analysis of the algorithm are presented.

18

Sterowanie pojazdami autonomicznymi z wykorzystaniem rozpoznawania z reprezentacją wiedzy

63%

Józefczyk J. , Szala M.

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2000

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tom z. 129

201-210

PL

W pracy jest rozważany problem sterowania jazdą grupy pojazdów autonomicznych. Zaproponowano hierarchiczną strukturę systemu sterowania z lokalnymi algorytmami sterowania jazdą pojedynczych pojazdów oraz z nadrzędnym algorytmem koordynacji jazdy, która jest realizowana z wykorzystaniem rozpoznawania z reprezentacją wiedzy. Do rozwiązania problemu rozpoznawania wykorzystano metodę rozpoznawania wieloetapowego. Zaprezentowano wstępną weryfikację algorytmu dla przypadku dwóch pojazdów, przeprowadzoną z wykorzystaniem symulacji komputerowej.

EN

The motion control problem of a group of AGVs is investigated. The hierarchical structure of the control system with motion control algorithms for local vehicles and with an upper movement co-ordinator is proposed. The movement coordinator is derived using knowledge based pattern recognition, with the data in the form of logical formulas. To solve the problem the multistage pattern recognition method is applied. The solution algorithm is initially verified via simulation for the case of two vehicles.

19

Routing flow-shop with buffers and ready times - comparison of selected solution algorithms

51%

Józefczyk J. , Markowski M. , Balgabaeva L.

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tom Vol. 5, No. 4

26--35

EN

This article extends the former results concerning the routing flow-shop problem to minimize the makespan on the case with buffers, non-zero ready times and different speeds of machines. The corresponding combinatorial optimization problem is formulated. The exact as well as four heuristic solution algorithms are presented. The branch and bound approach is applied for the former one. The heuristic algorithms employ known constructive idea proposed for the former version of the problem as well as the Tabu Search metaheuristics. Moreover, the improvement procedure is proposed to enhance the quality of both heuristic algorithms. The conducted simulation experiments allow evaluating all algorithms. Firstly, the heuristic algorithms are compared with the exact one for small instances of the problem in terms of the criterion and execution times. Then, for larger instances, the heuristic algorithms are mutually compared. The case study regarding the maintenance of software products, given in the final part of the paper, illustrates the possibility to apply the results for real-world manufacturing systems.

20

Data driven tests for univariate symmetry

51%

Inglot T. , Janic A. , Józefczyk J.

Probability and Mathematical Statistics

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2012

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tom Vol. 32, Fasc. 2

323--358

EN

We propose new data driven score rank tests for univariate symmetry around a known center.We apply both Schwarz-type and recently introduced data driven penalty selection rules. Some key asymptotic results regarding the test statistics are given and some asymptotic optimality properties proved. In an extensive simulation study, we compare the empirical behaviour of these tests to tests found in the recent literature to be powerful. We show that, for a broad range of asymmetric distributions, data driven tests have stable power, which is comparable to their competitors for typical alternatives and much greater for some atypical alternatives.